577 resultados para Metabólicos bioativos


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Among the new drugs launched into the market since 1980, up to 30% of them belong to the class of natural products or they have semisynthetic origin. Between 40-70% of the new chemical entities (or lead compounds) possess poor water solubility, which may impair their commercial use. An alternative for administration of poorly water-soluble drugs is their vehiculation into drug delivery systems like micelles, microemulsions, nanoparticles, liposomes, and cyclodextrin systems. In this work, microemulsion-based drug delivery systems were obtained using pharmaceutically acceptable components: a mixture Tween 80 and Span 20 in ratio 3:1 as surfactant, isopropyl mirystate or oleic acid as oil, bidistilled water, and ethanol, in some formulations, as cosurfactants. Self-Microemulsifying Drug Delivery Systems (SMEDDS) were also obtained using propylene glycol or sorbitol as cosurfactant. All formulations were characterized for rheological behavior, droplet size and electrical conductivity. The bioactive natural product trans-dehydrocrotonin, as well some extracts and fractions from Croton cajucara Benth (Euphorbiaceae), Anacardium occidentale L. (Anacardiaceae) e Phyllanthus amarus Schum. & Thonn. (Euphorbiaceae) specimens, were satisfactorily solubilized into microemulsions formulations. Meanwhile, two other natural products from Croton cajucara, trans-crotonin and acetyl aleuritolic acid, showed poor solubility in these formulations. The evaluation of the antioxidant capacity, by DPPH method, of plant extracts loaded into microemulsions evidenced the antioxidant activity of Phyllanthus amarus and Anacardium occidentale extracts. For Phyllanthus amarus extract, the use of microemulsions duplicated its antioxidant efficiency. A hydroalcoholic extract from Croton cajucara incorporated into a SMEDDS formulation showed bacteriostatic activity against colonies of Bacillus cereus and Escherichia coli bacteria. Additionally, Molecular Dynamics simulations were performed using micellar systems, for drug delivery systems, containing sugar-based surfactants, N-dodecylamino-1-deoxylactitol and N-dodecyl-D-lactosylamine. The computational simulations indicated that micellization process for N-dodecylamino-1- deoxylactitol is more favorable than N-dodecyl-D-lactosylamine system.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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JUSTIFICATIVA E OBJETIVOS: O dextran associado à solução hipertônica de cloreto sódio a 7,5% apresenta efeitos hemodinâmicos benéficos no controle prolongado da reanimação no choque hemorrágico. O objetivo deste estudo foi verificar se a associação do dextran à solução de cloreto de sódio a 7,5% apresentaria vantagens na avaliação imediata dos parâmetros hemodinâmicos e metabólicos na reanimação em modelo de choque hemorrágico controlado em cães. MÉTODO: Foram estudados 16 cães submetidos à hemorragia controlada até que a pressão arterial média atingisse 40 mmHg e permanecesse assim por até 30 minutos. Estes foram divididos em G1, com administração de NaCI a 7,5%, e G2, com administração NaCI a 7,5% combinada com dextran 70 a 6%, no volume de 4 mL.kg-1, durante três minutos. Foram avaliados os parâmetros hemodinâmicos e metabólicos. Consideraram-se quatro momentos: M1 - 10 minutos após o preparo cirúrgico, M2 - obtido na metade da fase de choque, M3 - obtido dois minutos após o final da administração das soluções, M4 - 30 minutos após o início da reanimação. RESULTADOS: Após a reanimação, não houve diferença significativa dos valores da FC, PAM, PCP e IRVS. O G2 apresentou valores maiores do IC em M4. Os valores da SvO2 foram menores no G1, final do experimento. A C(a-v)O2 foi maior no G1 nos momentos M3 e M4. Os valores do VO2 aumentaram nos dois grupos em M4 e os valores do lactato plasmático aumentaram progressivamente até M3 e diminuíram em M4. Houve aumento dos valores do Na plasmático e redução do hematócrito nos dois grupos. CONCLUSÕES: O G2 mostrou melhor desempenho hemodinâmico principalmente após 30 minutos do início da reanimação. Observou-se, também, maior expansão plasmática e melhor perfusão tecidual na associação do dextran ao NaCl a 7,5%.

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This article reviews the metabolism of fructose and sorbitol, their main clinical indications and the consequences of inadequate use. Fructose, an important carbohydrate in the diet, is present mostly in fruits and vegetables; it can also be synthesized from glucose in the organism, through the sorbitol. Fructose is known for its metabolism's inherent errors, whose clinical manifestations are potentially serious, as well as for its use as a glucose substitute in the diabetic patients' diet, due to its metabolism not being dependent from insulin. In the last years, especially in developed countries, the consumption of fructose has increased considerably, due to its use as a sweetener in industrialized foods. However, adverse side-effects may occur with the excessive ingestion of fructose, such as the increase in blood's triglycerides and cholesterol. Therefore, to know which are the patients' normal blood levels is quite important for establishing the safe amount of fructose to be prescribed, as well as for allowing the screening of metabolism diseases associated with fructose.

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Endophytic fungi are a rich source of new and biologically active natural products. They colonize a relatively unexplored ecological habitat and their secondary metabolism is particularly active, presumably due to metabolic interactions with their hosts. In the course of our continuing investigations for new and bioactive compounds from endophytic fungi from brazilian flora Alibertia macrophylla, Caseria sylvestris, Ocotea corymbosa, Cassia spectabilis, Piper aduncum, Cryptocaria mandioccana, Xylopia aromatica and Palicourea marcgravii were investigated. Forty two natural products were isolated and their structures were established on the basis of comprehensive spectral analysis, mainly using 1D and 2D NMR experiments. The compounds were tested in their antifungal, antioxidant, anticholinesterasic and anticancer activities.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Ciências da Motricidade - IBRC

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Pós-graduação em Ciências da Motricidade - IBRC

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)